Details

Autor(en) / Beteiligte

• Jia, C.L.
• Houben, L.
• Thust, A.
• Barthel, J.

Titel

On the benefit of the negative-spherical-aberration imaging technique for quantitative HRTEM

Ist Teil von

• Ultramicroscopy, 2010-04, Vol.110 (5), p.500-505

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2010

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Employing an aberration corrector in a high-resolution transmission electron microscope, the spherical aberration C S can be tuned to negative values, resulting in a novel imaging technique, which is called the negative C S imaging (NCSI) technique. The image contrast obtained with the NCSI technique is compared quantitatively with the image contrast formed with the traditional positive C S imaging (PCSI) technique. For the case of thin objects negative C S images are superior to positive C S images concerning the magnitude of the obtained contrast, which is due to constructive rather than destructive superposition of fundamental contrast contributions. As a consequence, the image signal obtained with a negative spherical aberration is significantly more robust against noise caused by amorphous surface layers, resulting in a measurement precision of atomic positions which is by a factor of 2–3 better at an identical noise level. The quantitative comparison of the two alternative C S-corrected imaging modes shows that the NCSI mode yields significantly more precise results in quantitative high-resolution transmission electron microscopy of thin objects than the traditional PCSI mode.